基于流体分离污泥的异质性:微生物活性和群落结构

生物流化床处理系统中的剩余污泥如果能够被识别为老化的污泥和高活性的污泥,并通过某一种物理方法加以原位分离,则有可能提高生物处理的效率.本文以构造流体力场实现基于比重分布不同污泥组分的分离,得到聚结型污泥与离散型污泥,考察了两种污泥在胞外聚合物、微生物活性和微生物群落结构方面的差异,并与降解活性相关联,以证明异质性的存在.研究发现:活性污泥这种异质性的存在归因于离散型污泥中的胞外聚合物含量高,亲水性更强,比重更小;聚结型污泥在基质利用效率、比耗氧速率方面优于离散型污泥;在废水生物处理系统的污泥中,聚结型污泥较离散型污泥具有微生物群落结构分布上的优势,种群丰度更高.研究结果证明了聚结型污泥和离散型污泥内部菌胶团存在着功能上的差异,前者是应该被保留的活性组分,后者应该作为剩余污泥加以分离排出.

The heterogeneity of the activated sludge based on fluid separation:The microbial activity and community structure

The identification and in-situ physical separation of aging and active sludge in the excess sludge in biological fluidized bed processing system could increase the efficiency of the biological treatment. Based on the difference in relative density, tightly bound sludge and loosely bound sludge were separated through centrifugal setting. The differences in extracellular polymeric substance (EPS), microbial activity and microbial community structure between these two kinds of activated sludge were investigated. Associated with degradation activity, the existence of heterogeneity in the activated sludge was proved. The results indicated that the heterogeneity in the activated sludge was due to the higher EPS content, stronger hydrophilia and lower density of loosely bound sludge. The substrate utilization efficiency and specific oxygen uptake rate (SOUR) of tightly bound sludge were higher than loosely bound sludge. The microbial population in the tightly bound sludge was more abundant than that in loosely bound sludge in biological wastewater treatment. These results proved the functional differences of the inner zoogloea between tightly bound sludge and loosely bound sludge, which demonstrated the former should be kept as active component and the latter should be discharged as excess sludge.